mariadb mad file take all space in hard drive

Solution 1:

Multiply the maximum number of rows your DBA thinks is practical for your joins by 10 and set that as max_join_size.

Set tmp_disk_table_size so that your file system does not exceed 90% full.

Tell whomever wrote the query in question about the limits you put in place to preserve availability. Have a cost benefit discussion of writing more efficient queries versus throwing memory and storage at the problem.

And further tune your temporary tables now that you know what they are called. From Stack Overflow: How can I limit the size of temporary tables?

Solution 2:

That file is a temporary table that MariaDB wrote to disk because it was too large to keep in memory. If you've stopped the database, then the query which caused the table to be created is no longer running, so it is safe to delete the file. But you also need to investigate why that file was created and fix the underlying problem, or it will happen again.